1. Field of the Invention
This invention relates to a system for providing communication among control devices within a vehicle, such as an automotive vehicle.
2. Description of the Prior Art
Some modern automotive vehicles have electronic control devices, such as an electronic engine control device, an electronic transmission control device, and an electronic shock absorber control device. For example, in an electronic engine fuel supply control device, an actuator or actuators such as fuel injection valves are controlled in accordance with engine operating parameters detected via sensors. It is known to connect these vehicle electronic control devices via a point-to-point type communication system or network.
The known vehicle communication system of the point-to-point type has the following problems, however.
(A) Since the communication is of the point-to-point type, information data inputted into anyone respective control devices are generally exclusively usable. In order to make information data usable in common to the respective different devices, additional interfaces or auxiliary communication devices are necessary. The auxiliary communication devices occupy a large space and increase the cost of the vehicle.
(B) The controls by the respective vehicle ccntrol devices are basically mutually independent. The independent controls generally cause an extremely great total length of connecting wires. Such long connecting wires occupy a large space and sometimes cause communication data to be contaminated by noise.